Advertising display unit



FIG. 1 is a front elevational view of an advertising display unit, showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a front perspective view thereof.

The broken line disclosure of the indicia in all views is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an advertising display unit, substantially as shown and described. 